Key operated electric switch



Sept. 29, 1931. I R. A MILLERMASTER ET AL 1,325,325

KEY OPERATED ELECTRIC SWITCH Filed May 5, 1930 Patented Sept. 29, 1931 UNITED STATES PATENT. OFFICE RALPH A. MILLER-MASTER .AN'D CARSTEN PETERSEN, OF MILWAUKEE, WISCONSIN, AS-

SIGNOR T CUTLEB-, me, OF MILWAUKEE, WISCONSIN, A CORPORATION OF DELAWARE HY OYEBATED ELECTRIC SWITCH Application filed Kay 5, 1930. Serial No. 449,826.

This invention relates to improvements in key-operated electric switches, and although not limited thereto the invention is particularly applicable to enclosed flushmounted snap switches of the toggle type.

An object of the invention is to generally improve the details of construction and operation of key-operated switches of the aforementioned character.

Another object is to provide a. novel form of key-guard or guide.

Another object is to provide novel means cooperating with said guard to prevent fouling of the key with respect to the switch mechanism.

Another object is to provide a novel form of rock-lever to be engaged by the key.

Another object is to provide novel means to insure against operation 0 said rocklever by any element other than said key.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate an embodiment of the invention which will now be described, it being understood that the embodiment illustrated is susceptible of modification within the scope of the appended claims.

In the drawings, Figure 1 is a top plan view of a key-operated single-pole electric switch constructed in accordance with our invention. 7

Fig. 2 is an enlarged vertical sectional View, on the line 2-2 of Fig. 1,the key being shownin operative position.

Fig. 3 isa similar view, on the line 3-3 of Fig. 1.

Fig. 4 is a top plan view of the lower section of the insulating base or housing and the switch mechanism.

Fig. 5 is a perspective view of the keyguard or guide element of the swltch.

Fig. 6 is a perspective view of the several parts of the rock-lever prior to assembly thereof and V Fig. 7 is a perspective view of the key.

Referring to the drawings, the numerals 10 and 11 designate, respectively, the base and cover sections of insulating material which provide a housing for the snapswitch mechanism. Said mechanism comprises essentlally a stamped sheet metal frame 12 of substantially U-shape in cross section, said frame having foot portions 13 and 14 adapted to seat against or rest upon a pair of soft rubber blocks or cushions 15 and 16 carried by the' base section 10 of the housing. Pivotally interlocked with the frame, in the manner best illustrated in Fig. 3, is a flat punched sheet metal contact carrier 17 of substantially bail form,said carrier having attached thereto but insulated therefrom a pair of resilient contactor elements 18, 19 for cooperation with the stationary contacts 20, 21 carried by section 10. Engaged with an abutment 22 on, carrier 17 and biasing the latter to one extreme position or the other is one end of a spring 23, said spring being preferably enclosed by a notched orslotted cylindrical member 24 having an indented closed end to be engaged by the rock lever of the switch.

The insulating casing parts are secured to each other and to suitable supporting lugs or cars 25 and 26 as by means of a pair of screws 27 and 28. I

All of the parts thus far described are identical with the parts of the single-pole switch shown and described in the copending application of Ralph A. Millermaster, Serial No. 397,495, filed October 5, 1929, and more specific description of such parts herein is deemed unnecessary. Also, as will be apparent, our improvement ma be readily incorporated in such switches o the doublepole, three-way or four-way type.

The rock-lever 29 comprises a flat sheet metal punching'having a rounded projection 30 for cooperative engagement with the aforementioned indented end of member 24, said lever also having relatively widely divergent curved arms 31 and 32 which alter nately engage the soft rubber blocks 15 and 16 to yieldably limit oscillatory movements of said lever.

The upper edge of lever 29 is notched or cut away, as shown at 33 and 34 in Fig. 6, to provide an integral substantially rectangular stud or projection 35 which is adapted to penetrate a correspondingly shaped opening 36 in the integral cross-piece or connecting portion 37 of a substantially U-shaped member or yoke 38, said portion 37 having notches 39 and 40 to interlock with the notched portions 33 and 34 of lever 29 whereby relative lateral movement of the lever with respect to yoke 38 is prevented. The projection 35 is upset over the connecting portion 37 as indicated at 3 5 in Fig. 2, to rigidly and permanently secure said parts to each other.

The parallel upstanding arms 41 and 42 of yoke 38 are provided near the lower ends thereof with alined pivot openings, one of which is shown" at 43 in Fig. 6. A headed pivot pin 44 penetrates said openings in the yoke and corresponding openings in the upstanding arms of frame 12,the end ofsaid pin being preferably u set as shown at 44 in Fig. 3 to retain sai parts in assembled relation. It will be understood, however, that the pivot pin 44 will be held against substantial endwise displacement by the walls of the recess in the upper'casing section, and hence the aforementioned upsetting operation may be omitted if desired. The yoke 38 when initially blanked may be provided with a pair of openings or perforations 45 (Fig. 6) to facilitate forming of the piece.

The upper ends of the arms 41 and 42 of yoke 38 are enlarged to provide curved or segmental edges 41 12, and said edges are respectively provided with notches 41' and 42 oppositely offset from the vertical plane of the pivot openings 43 in the arms 41 and 42 of the yoke.

A punched and stamped sheet metal key d6 (Fig. 7) is provided with oppositely proecting laterally offset arms 47 and 48 which are adapted for joint engagement with the notches 41", 42 the lower edges of said arms being preferably slightly oitset upwardly to provide shoulders 47 4:8 to insure proper seating of the key arms within sald notches.

Resting upon the upper face of the top section 11 of the insulating housing and overlying the yoke 38 is a key-guard or guide member 49 (Fig. 5), said member being stamped from relatively thin sheet metal to provide an intermediate portion 50 of upwardly curved segmental form to provide clearance for the upper segmental end portions of the yoke arms 41 and 42. The vertical sides 51 and 52 of intermediate portion 50 insure against access'to the yoke arms by means other than the key 46. As shown, the opposite ends 53 and 54 of member 49 are offset downwardly whereby the same may be clumped beneath the inner ends ofsupporting lugs 25 and 26 by the assembly of the other parts of the switch.

The segmental or arcuate surface 50 of member 49 is provided with a relatively nar= row medialslot 55 which is adapted to provide clearance for the'shank or neck portion 46 of the key,four equally spaced branch slots 56, 57, 58 and 59 extending alternately in opposite directions at right angles to the slot 55. Thus the slots 56, 55 and 57 provide for insertion of the arms 47,48 of the key into notches 41 42 when the parts of the switch mechanism are in one extreme position, and the slots 58, 55 and 59 provide for insertion of the key arms into said notches when the switch parts are in their opposite extreme position.

As best shown in Figs. 1 and 2, however, when the switch parts are in one extreme position the branch slots 56 and 57 are obstructed by the arcuate edges 42 and 41, respectively, of the yoke arms, thus insuring insertion of the key at the proper angle to provide for operation of the switch. Similarly the branch slots 58 and 59 will be obstructed by said arcuate edges 42 and 41 of the yoke arms when the switch parts are in their opposite extreme position.

The guard or guide member 49 is preferably applied so that the branch slots 58 and 59 will be cleared in the on position of the switch (as shown in Figs. 1 and 2), wherefore the legend shown at 60 may be utilized to indicate the proper manner of mounting the switch in the wall. In this way upward movement of the key as a handle will result in on positioning of the switch and downward movement of the key will result in off positioning of the switch,-which is the preferred arrangement in switches of this character.

In order to prevent tampering with the switch mechanism, such as by inserting a wire or nail or the like which might clear the slot 55, we preferably provide a strip of spring metal 61 which is bent or bowed to substantially the shape illustrated in Figs. 2 and 6,-said strip being rigidly secured to the arms 31 and 32 in any suitable manner. such as by spot welding at the points 62 and 63 indicated in dotted lines in Fig. 2. The strip 61 thus acts as a guard to deflect any inserted tool or element from operative engagement with the rock lever.

l t will also be observed that my employing an enclosing insulating casing of the character illustrated it is not possible to tamper with the switch mechanism even though the usual flush-or cover plate (not shown) is removed. The effectiveness of the means herein disclosed for locking the switch mechanism-in on or of? position will be appreciated by those skilled in the art.

"What we claim as new and desire to secure by Letters Patent is:

1. in a key-operated electric switch, in combination, a horizontally divided two-part insulating casing, supporting lugs at oppoprojecting outwardly through one of said casing sections, and a key-guard or guide seated upon said last-mentioned casingsection and having an arcuate portion adapted to accommodate the arcuate edges of said rock-lever, said guard having downwardly offset end ,portions adapted to underlie said supporting lugs whereby said guard may be securely clamped in position. v

2. In a. key-operated electric switch, in combination, a horizontally divided two-part insulating casing, supporting lugs at opposite ends of said casing, common means at each end of said casing for securing the easing sections to each other and to said supporting lugs, snap switch mechanism enclosed within and supported by said casing sections jointly, said switch mechanism having a rock-lever with arcuate edge portions projecting outwardly through one of said casing sections, a key-guard or guide seated upon said last-mentioned casing section and having an arcuate portion adapted to' accommodate the. arcuate edges of said rock-lever, said guard having downwardly offset end portions adapted to imderlie said supporting lugs whereby said guard may be securely clamped in position, the arcuate edges of said rock-lever each having a substantially vertical notch arranged in staggered relation to each other, and said guard having a narrow intermediate slot and two pairs of branch s lots, the branch slots of each pair extending 'in opposite directions and being located in staggered relation to each other.

3. In a key-operated electric switch, in

combination, a horizontally divided twopart insulating casing, supporting lugs at opposite ends of'said casing, cormnon means at each end ofzsaid casing for securing the casing sections to each other and to said supporting lugs, snap switch mechanism enclosed within and supported by said casing sections jointly, said switch mechanism having a' rock-lever with arcuate edge portions projecting outwardly through one of said casing sections, a key-guard or guide seated upon said last-mentioned casing section and having an arcuate portion adapted to accommodate the arcuate edges of said rock lever, said guard having-downwardly offset end portions adapted to underlie said sup porting lugs whereby said guard may be securely clamped in position, the arcuate edges of said rock-lever each having a substantially vertical notch arranged in staggered relation to each other, and said guard having a narrow intermediate slot and two pairs of branch slots, the branch slots of each pair extending in opposite directions and being located in staggered relation to each other, the notches in said rock-lever being adapted to register with one pair of branch slots in each extreme position of said rock-lever, and the other pair of branch slots being obstructed by other portions of said arcuate edges in each instance.

4. A key-operated snap switch of the toggle type, comprising a sheet metal frame of substantially U-shape in cross section, a contactor pivotally supported by said frame, a compression spring biasing said contactor to one extreme position or the other, a rocklever to shift said spring to opposite sides of the center of oscillation of said contactor, said rock-lever comprising a flat unched sheet metal part and asubstantlally U- shaped member to which sai'dpart is rigidly secured, said U-shaped member being pivotally supported by said frame, the arms of said U-shaped member having arcuate upper edges and said edges having notches or slots arranged in staggered relation to each other, and a key guide or ard formed to accommodate said arcuate e ges and having a relatively narrow intermediate slot and two pairs of offset and oppositely extending branch slots, the notches aforementioned being adapted to register with each pairof branch slots in only one of the respective extreme positions of said rock-lever.

5. As an article of manufacture, a rocklever for key-operated electric snap switches comprising a flat sheet metal punching, the upper edge of said punching being notched to provide a stud with vertical shoulders spaced therefrom, a substantially Ushaped punched and stamped metal piece having an opening in its bottom portion to receive said stud and notches in its side edges to receive said vertical shoulders, said stud being upset over said bottom portion to rigidly secure said parts to each other, and the arms of said U-shaped piece having arcuate edges each provided with a substantially vertical notch, said ,notche's being located in stagger'ed relation to each other.

6. As an article of manufacture, a rocklever for key-operated electric snap switches comprising a fiat sheet metal punching having an integral stud formed at the upper edge thereof and vertical shoulders spaced from oppositesides of said stud, a substantially U-shaped punched and stamped metal piece having an opening to accommodate said stud and notches to accommodate said vertical shoulders, said stud being upset over said U-shaped piece to rigidly and permanently secure said parts to each other, the upper edges of said U-shaped piece having substantially vertical notches arranged in staggered relation to each other, and an upwardly bowed spring metal member positioned between the arms of said U-shaped piece, the ends of said member being rigidly attached to said first mentioned sheet metal punching.

7. A-key-operated snap switch of the toggle type, comprising a sheet metal frame of substantially U-shape in cross section, a contactor pivotally supported by said frame, a compression spring biasing said contactor to one extreme position or the other, a rocklever to shift said spring to opposite sides of the center of oscillation of said contactor said rock-lever comprising a flat punched sheet metal part and a substantially U- shaped member to which said part is rigidly secured, said U-shaped member being pivotally supported by said frame, the arms of said U-shaped member having arcuate upper edges and said edges having notches or slots arranged in staggered relation to each other, a key guide or guard formed to accommodate said arcuate edges and having a relatively narrow intermediate slot and two pairs of offset and oppositely extending branch slots, the notches aforementioned being adapted to register with each pair of branch slots in only one of the respective extreme positions of said rock-lever, and an operating key comprisin a punched and stamped sheet metal -mem r having flat shank and body portions of substantially equal width located in the same plane, said member having branch portions extending in opposite directions from the respective edges of said body portion at substantially right angles to the plane of the latter.

8. A key-operated snap switch of the toggle type, comprising a sheet metal frame of substantially U-shape in cross section, a contactor pivotally supported by said frame, a compression spring biasing said contactor to one extreme position or the other, a rocklever to shift said spring to opposite sides of the center of oscillation of said contactor, said rock-lever comprising a fiat punched sheet metal part and a substantially U- shaped member to which said part is rigidly secured, said U-shaped member being pivotally supported by said frame, the arms of said U-shaped member having areuate upper edges and said edges having notches or slots arranged in staggered relation to each other, a key guide or guard formed to accommodate said arcuate edges and having a relatively narrow intermediate slot and two pairs of offset and oppositely extending branch slots, the notches aforementioned being adapted to register with each pair of branch slots in only one of the re spective extreme positions of said rock-lever, and an operating key comprising a punched and stamped sheet metal member having a flat shank and body portions of substantially equal width located in the same plane, said 

